While the ability to manipulate bacterial and mammalian cells by hybrid DNA technology has been available for almost a decade, it was only in 1983 that the first successful expression of an exogenous gene in a plant cell was achieved. Lack of success in transforming plant cells was due at least in part to a lack of suitable vectors and methods for regenerating plants from transformed cells. A vector which has been used with significant success for transformation of plant species has been Agrobacterium. To date, dicotyledenous species, particularly petunia, tomato and tobacco have been the primary plant materials used in Agrobacterium transformation studies. The procedures for regeneration from somatic cells as well as for transformation are well established for these species. However, for some of the world's major agricultural crops, such as legumes, genetic engineering has been less successful either because of poor regenerability and/or transformation by Agrobacterium.
It would be of interest to develop more efficacious methods for transforming legumious plant cells outside the normal host range of Agrobacterium and to regenerate plants from transformed somatic cells.
Relevant Literature
Thin epidermal layers from hypocotils, stems, and pedicels, have been used for morphological studies in various plants such as tobacco, rapeseed, and winged bean. See for example Van et. al. Biotechnology in Agriculture and Forestry. (1986) 2:556-567 and Kamate et. al. Canadian J. Botany (1981) 59:775-781. Charest et. al. Theor. Appl. Genet (1988) 75:438-445 disclosed the use of thin layer explants for rapeseed transformation mediated by Agrobacterium. Transgenic plants were generated from the transformed thin layer explants.